Data transmission method with a lower probability of erroneous rejection of data

ABSTRACT

A method transmits data between a base station and a terminal in a communication system. According to said method, data is transmitted subdivided into time segments (Zs,R) from the base station (HS-DSCH) that is jointly used by several terminals via the base station informs the terminals, and the base station informs the terminal via one of at least two control channels method encompasses the following: the at least two control channels (HS-SCCH 1,  HS-SCCH 2 ) are monitored by the terminal; the terminal receives the piece of control information on a first of the at least two control channels (HS-SCCH 1 ) within a first time segment (ZS 1,  R 1 ); an individual decision parameter is generated for each of the parts (P 1,  P 2 ) of control information based on the content of the respective part (P 1,  P 2 ) of control information: an overall decision parameter is determined based on the individual decision parameters; data received on the data channel (HS-DSCH) and the piece of information received on the control channel (HS-SCCH 1 ) are rejected in accordance with the overall decision parameter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and hereby claims priority to PCTApplication No. PCT/EP2004/052148 filed on Sep. 13, 2004 and GermanApplication No. 10345638.4 filed on Sep. 29, 2003, the contents of whichare hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The invention relates to a data transmission method in a communicationnetwork, especially cellular radio network, in which data, especiallydata packets of a packet-oriented data service, are transmitted over adata channel jointly used by several terminals and several jointly usedcontrol channels are used for signaling the specific mobile station(s)for which the data is intended.

In UMTS (Universal Mobile Telecommunication System) data packets aresent to User Equipment (UE) over the High-Speed Downlink Shared Channel(HS_DSCH). The associated control information is transmitted in parallelover the High-Speed Shared Control Channel (HS_SCCH). A maximum of fourof these HS_SCCHs are assigned to a mobile station. So that thereceiving mobile station can recognize that the information on theHS_SCCH and the data on the HS_DSCH is intended for it, the controlinformation is linked to identification information specific to a mobilestation. For a more precise definition of terms the reader is referredto the description of the Figures below.

In UMTS the HS_DSCH is shifted in relation to the HS_SCCH by two timeslots and three time slots of both the HS_SCCH and of the HS_DSCHcorrespond to one information unit of the physical layer (the length ofan information unit is referred to as a subframe).

As well as the mobile station-specific identification information a unitof the HS_SCCH also contains information about

-   -   the HS_DSCH spreading codes or channelization codes used,    -   the modulation scheme, for example QPSK (Quadrature Phase Shift        Keying) or 16 QAM (16 Quadrature Amplitude Modulation),    -   the number of the data bits which are transferred from the        physical layer to the next higher layer,    -   the indication as to whether this is a first data transmission        or a retransmission of the data,    -   the HARQ process number,    -   the information relating to the mapping specification of the        data bits to the 16 QAM modulation used and regarding the rate        adaptation pattern.

The information relates in each case to the HS_DSCH information unittransmitted 2 time slots later.

In UMTS a mobile station must monitor up to four HS_SCCHs if it has notalready received data intended for it in the immediately precedingHS_SCCH unit. An example with 4 HS_SCCHs is selected below, but adifferent number is similarly possible, such as 2 or 3. Conversely, inthe UMTS standard it is true to say that a mobile station which receivesthe control information intended for it on one of the HS_SCCHs, in thesubsequent interval of the length of three time slots only monitors oneHS_SCCH, this being the HS_SCCH on which the control information waspreviously received. The reason for this is that it allows parts of thereceiver hardware which will be needed for HS_SCCH receiving, in theevent of data transmission on the HS_DSCH, to be able to be used forHS_DSCH receiving and thereby fewer resources are needed overall. Thisis referred to as the consecutive scheduling rule.

Furthermore different categories of mobile stations, i.e. mobilestations with different service features, are used in UMTS. As regardspacket-oriented high-speed data transmission a mobile station isidentified in accordance with its category, especially in the followingcapabilities

-   -   the maximum number of HS_DSCH channelization codes which it can        simultaneously receive and process in an HS_DSCH unit,    -   the minimum period of time between two consecutive data        transmissions on the HS_DSCH which it can process,    -   the modulation scheme (QPSK, 16 QAM) which it can process,        and further parameters.

In addition the physical layer is informed via signaling by higherlayers of the OSI (Open system Interconnection) models about the numberof Hybrid Automatic Repeat Request (HARQ) process and the maximumtransport block size or packet size.

An example of inconsistent information in the case of UMTS is if thenumber of HS_DSCH channelization codes used transmitted in the HS_SCCHunit is greater than the maximum number of HS_DSCH channelization codeswhich the mobile station must be able to process in accordance with itscategory or/and if the number of the HARQ process is higher than thenumber of HARQ processes configured for this mobile station.

If a mobile station establishes that the information in an HS_SCCH unitwhich it evaluates in accordance with its identification as intended forit does not contain consistent information, the physical layer can inthis case reject the information and not forward it. The advantage ofthis method is that the likelihood of a transfer of erroneous packetsfrom the physical layer to higher layers is reduced by those packetswhich appear to contain inconsistent information being filtered out.Since the inconsistent control information itself is not passed on tohigher layers since it is only needed in the physical layer, suchfiltering can only be performed in the physical layer. Inconsistent datacan under some circumstances lead to serious malfunctions at higherlayers, thus great importance has been placed in the UMTS specificationon avoiding such errors as far as possible. In addition to furthermethods such as checksum tests, the consistency checking described is amethod for avoiding such erroneous behavior.

It can now be the case that data which could actually have beencorrectly received is also rejected by such consistency checking: Forexample it can be the case that a mobile station is requested to used 5HS_DSCH spreading codes or channelization codes which corresponds to itsmaximum capability. Errors in transmission can now mean that the mobilestation incorrectly believes that it has to receive 15 codes. If,instead of this, it now receives the maximum possible number of codes,namely 5, it would have corrected the incorrect transmission of thecontrol information using this method. The mobile station should notattempt however to correct errors in control information but insteadshould detect errors and reject the entire data frame.

The disadvantage of this is that data can be rejected incorrectly.

SUMMARY OF THE INVENTION

Using this related art as its starting point, one possible object of thepresent invention is to create a simple option for reducing theerroneous rejection of data in a communication network.

The inventors propose a communication network in which data istransmitted between a terminal and a base station over a data channelwhich can be used by one or more, i.e. at least two, terminals. The datais subdivided into individual time segments in such cases. Furthermore anumber, i.e. at least two control channels, are provided on which theterminal listens in, and on one of these control channels the terminalwill be informed via control information if a data transmission is to beundertaken later, i.e. in a subsequent time slot over the data channel.

If the terminal receives the control information on one of the controlchannels, it analyzes its contents, especially as to whether the controlinformation is actually directed to it. The control information has aplurality of parts, that is at least one first control informationcomponent and one second control information component. In this case thefirst control information component can be received in a first timesegment and the second control information component in a subsequentsecond time segment.

Each of these pieces of control information is analyzed, and on thebasis of this analysis, a decision parameter is generated for each ofthese pieces of control information. An overall decision parameter forthe control information is determined by these individual decisionparameters, which is then used to determine whether the data received onthe data channel is to be rejected, i.e. not processed further,especially not forwarded to higher layers of the OSI model. Thisrejection can for example be undertaken in a third time segmentfollowing the first or the second time segment.

The fact that the overall decision parameter is composed of a pluralityof individual decision parameters reduces the probability of anincorrect decision.

The method is especially advantageous if the overall decision parameteris also used to define the control channel or control channels on whichthe terminal is to listen in in one or more subsequent time segments,e.g. the third time segment. This has the advantage that the computingeffort in the terminal is reduced if the latter no longer has to listenin on all control channels but only on one or more specific controlchannels.

In particular the terminal can continue to listen on the at least twoabove-mentioned control channels, for example if a piece of controlinformation is classified as not relating to the terminal (for examplebecause the data is not able to be processed by the terminal).

In a further development there is provision for the overall decisionparameter to be able to assume two values, for example a positive valueif the control information relates to the terminal and a negative valueif the control information does not relate the terminal. Thus forexample the decision can be made as to whether the terminal listens inon all control channels or only on the control channel on which it hasreceived control information.

The overall decision parameter can especially be composed of theindividual decision parameters such that it only then assumes a positivevalue if all the individual decision parameters are also positive.

The communication system involved can for example be a UMTS system.

In relation to the situation depicted at the start in UMTS theprobability is thus reduced of the transmission immediately followingthe transmission of an inconsistent piece of information (an HSDPAframe) being missed by a terminal or a mobile station. The startingpoint for this is the consecutive scheduling rule described above andthe fact that it is highly probable that there is an HS_SCCH false alarmif the decoding of the HS_SCCH information unit supplies inconsistentinformation. Thus the situation is prevented in which a false alarm ondetection of the control channel prevents data of the next frame frombeing able to be received. Furthermore in a UMTS system as described atthe start, the probability of detecting a false alarm is increased bythe inclusion of further criteria for consistency checking. (A mobilestation which only supports QPSK modulation with HSDPA can, byadditionally performing a consistency check in relation to themodulation scheme in the HS_SCCH information unit directed to it, reducethe probability of a false alarm). A false alarm in this context occursif a mobile station, on decoding the identification information,incorrectly assumes that the identification information matches itsidentification although no transmission has actually been performed bythe base station for this mobile station, but instead a transmission canhave been performed for another mobile station or even no transmissionat all.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention willbecome more apparent and more readily appreciated from the followingdescription of the preferred embodiments, taken in conjunction with theaccompanying drawings of which:

FIG. 1: a communication system with a base station and a terminal; and

FIG. 2: a subdivision of control channels and data channels into 4 timeslots

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout.

Before the figures are presented in detail an initial explanation willbe provided for a plurality of terms used:

A communications system or communication network is to be seen as astructure for the exchange of data. This can for example involve acellular mobile radio network, such as the GSM (Global System of MobileCommunications) or the UMTS (Universal Mobile Telecommunications System)network. A communication network comprises at least two connectionnodes, which means that this term also covers point-to-pointconnections.

Terminals and base stations are generally provided in a communicationsystem, these being connected to each other via a radio interface. InUMTS the communication system or radio transmission network at leastfeatures base stations, also referred to here as NodeBs, as well asRadio Network Controllers (RNC) for connecting the individual basestations. The Universal Terrestrial Radio Access Network UTRAN is theradio part of an UMTS network in which the radio interface is also madeavailable for example. A radio interface is always standardized anddefines the totality of the physical and protocol definitions for dataexchange, for example the modulation method, the bandwidth, thefrequency range, access methods, security procedures and also switchingtechniques. The UTRAN thus comprises at least base stations as well asat least one RNC.

A base station is a central unit in a communications network, which inthe case of a cellular mobile radio network, serves terminals within acell of the mobile radio network via one or more radio channels. Thebase station provides the air interface between base station andterminal. It takes over the handling of radio operation with the mobilesubscribers and monitors the physical radio connection. In addition ittransfers payload and status messages to the terminals. The base stationdoes not have a switching function but merely a service provisionfunction. A base station comprises at least one transceiver unit.

A terminal can be any communication terminal via which a usercommunicates in a communication system. This includes for example mobileradio terminals such as mobile telephones or portable computers with aradio module. A terminal is often also referred to as a “mobile station”(MS) or as User Equipment (UE) in UMTS.

In mobile radio a distinction is made between two connection directions.The downlink (DL) direction identifies the direction of transmissionfrom the base station to the terminal. The uplink (UL) directionidentifies the opposite direction of transmission from terminal to basestation.

In broadband transmission systems, for example a UMTS mobile radionetwork, a channel is one part of an overall transmission capacityavailable. Within the context of this application a wirelesscommunication path is referred to as a radio channel.

In a mobile radio system, for example UMTS, there are two types ofphysical channels available for transmission of data: Dedicated channelsand common channels. With dedicated channels a physical resource isreserved only for the transmission of information for a specificterminal. With common channels information can be transmitted which isintended for all terminals, for example the Primary Common ControlPhysical Channel (P-CCPCH) in the downlink or all terminals share aphysical resource. This is the case with HS_PDSCH over which data issent to a terminal depending on the connection quality at the terminal.

In mobile radio systems in accordance with UMTS for example, as well ascircuit switched services, in which a connection is permanentlyallocated for its duration, packet switched services are also provided.

To co-ordinate the timing of the data transmission or of signalingprocedures, a transmission is subdivided into timeslots or slots. A timeslot in the UMTS system lasts for 0.666 ms.

A further time segment in UMTS, especially in connection with HSDPA, isa subframe containing 3 time slots. A frame as a further time segment inUMTS contains 15 time slots

FIG. 1 shows a communication network CN. A base station sends data overthe High-Speed Downlink Shared Channel (HS_DSCH) as data channel to aterminal or user equipment UE. It indicates a transmission on the firstHigh-Speed Shared Control Channel HS_SCCH1 or on the second High-SpeedShared Control Channel HS_SCCH2 as its control channel. Two controlchannels are typically selected in the Figure but any number greaterthan two can also be selected. The terminal features at least onetransceiver unit and a processor unit for processing the data.

Control information which can include a plurality of pieces of controlinformation is sent out via the control channels.

FIG. 2 shows a typical timing structure of control channels HS_SCCH1 toHS_SCCH4 and a data channel HS_DSCH.

The four control channels are transmitted in parallel from the basestation. Each of the four control channels HS_SCCH1 to HS_SCCH4 featuresa first part P1 on which a first piece of control information istransmitted and a second part P2 on which a second piece of controlinformation is transmitted. Identifying information to identify theterminal can be accommodated in a first part P1, for example theidentification number of the terminal. Only one data channel HS_DSCH islisted for example. Each of the channels is subdivided into subframes ofwhich the first subframe R1 and a second subframe R2 are shown in theexample. These subframes are further subdivided each into threetimeslots ZS 1, ZS 2 and ZS 3.

The data channel HS_DSCH is offset in relation to the control channel by2 timeslots. The first part of a control channel (HS_SCCH1-HSCCH4) issent before the associated data channel HS_DSCH, with a gap of one timeslot between the end of the control channel (HS_SCCH1-4) and thebeginning of the data channel HS_DSCH. The second part P2 of the controlchannel HS_SCCH overlaps with the associated data channel HS_DSCH anddoes this by the length of one time slot. The exemplary embodimentsdepicted below relate to the UMTS standard, that is to a UMTS mobileradio network. In the labels the abbreviations already used above areused directly to identify the channels. The corresponding method canhowever also be applied to other standards for which the correspondingtransmission methods are provided. The reader is also referred to theintroductory explanations especially relating to consistency checkingand to the following abbreviations:

HSDPA: High Speed Downlink Packet Access

HS_DSCH: High-Speed Downlink Shared Channel (HSDPA DL data channel)

HS_SCCH: High-Speed Shared Control Channel (HSDPA DL control channel).

A mobile station which only supports QPSK modulation with HSDPA can, byadditionally performing a consistency check, as described at thebeginning in relation to the modulation schemes, reduce the probabilityof false alarms in the HS_SCCH information unit directed to it.

A mobile station which receives an HS_SCCH Information Unit directed toit especially performs one or more of the consistency checks listedbelow:

-   -   The mobile station is to check whether the information “pber”,        that is the number of channelization codes used on the HS_DSCH,        is less than or equal to the maximum number of codes which it        can process.    -   The mobile station is to check whether the decoded modulation        scheme is allowed in accordance with its capabilities.

If at least one of the above-mentioned consistency checks fails, themobile station is to reject the data on the physical layer and behave asthough no HS_SCCH information unit directed to it had been received,i.e. the monitoring of all four HS_SCCHs in the following HS_SCCHsubframe is continued. This is also possible in time since theconsistency checks described can be performed after the decoding of thefirst HS_SCCH time slot. This is still possible before the time at whichthe receive devices must be switched to receive the following HS_SCCHsubframe. Furthermore the receive devices can only be switched toreceive the HS_DSCH if this information is present since the receivedevices can only then be switched to receive the correct channelizationcodes or channel coding information. Furthermore the mobile stationshould check whether the decoded HARQ process number and the decodedvariable of the specified transport block is less than or equal to themaximum values transmitted from the higher layers via signaling. Bycontrast with the checks discussed in the previous paragraph, this checkcan only be made after the receipt of third time slot of the HS_SCCHsubframe. At this point in time the receive devices and have alreadybeen switched to receive the HS_DSCH, so that in this case it is nolonger possible, instead of the HS_DSCH, to monitor all four HS_SCCHs inthe following HS_SCCH subframe. If at least one of the consistencychecks fails the mobile station (physical layer) should reject the data,even if data has already been received on the HS_DSCH (at least partly).

The following methods are provided in particular:

-   a) A method for data transmission in a cellular radio network in    which data packets of a packet-oriented data service are transmitted    via a data channel shared by a plurality of mobile stations    (HS_DSCH) and in which a plurality of shared control channels    (HS_SCCH) are used to signal for which specific mobile station(s)    the data is intended (and further parameters), with the data channel    being delayed in time in relation to the control channels.-   b) Furthermore a method as previously described, in which, after    detection of the receipt of an HS_SCCH information unit on one of    the shared control channels, receipt is only on the control channel    (HS_SCCH) on which the immediately preceding information unit was    received for a receiver unit in the immediately following subframe.

An information unit can especially be regarded here as a piece ofcontrol information.

-   c) Furthermore a method as previously described in which at least    one part of the received HS_SCCH information unit is subjected to a    consistency check, and in the event that at least one inconsistency    is established, the data is not passed on from the physical layer to    higher layers. Inconsistency means especially that the information    concerned cannot be processed by the terminal.-   d) Furthermore a method as previously described in which at least    one part of a detected HS_SCCH information unit is subjected to a    consistency check, and if an inconsistency is present, in the    immediately following subframe data is received on a plurality of    control channels (HS_SCCH), if an inconsistency is not present in    the immediately following subframe, receiving is merely on the    control channel (HS_SCCH) on which the HS_SCCH information unit was    detected in the current subframe.-   d1) A further development of this is especially a method as    previously described in which at least two parts (first part, second    part) of a detected HS_SCCH information unit are subjected to a    consistency check and, if an inconsistency is present in one part    (first part), the data is not passed on from the physical layer to    higher layers, and in the immediately following subframe receiving    is on a plurality of control channels (HS_SCCH), and if an    inconsistency is present in the other part (second part) only the    data is not passed on from the physical layer to higher layers.-   d11) This method can be developed to the extent that if an    inconsistency is not present, receiving in the directly following    subframe is merely on the control channel (HS_SCCH) on which the    HS_SCCH information unit was detected in the current subframe.-   d2) The method as illustrated under d) can be developed to the    extent that the one part (first part) is sent before the data    (HS_DSCH) and the other part (second part) overlaps at least partly    in time with the data (HS_DSCH) or is sent after it in time.-   e) Each of the methods can be developed so that the consistency    check relates to the number of HS_DSCH channelization codes.-   f) Furthermore the method can be modified so that a consistency    check relates to the modulation scheme.-   g) Furthermore a consistency check can be performed on the decoded    information on the HS_SCCH relating to the number of data bits    transferred from the physical layer to the next higher layer and/or    the HARQ process number. HARQ process number is taken in this case    to mean the process number for a specific transmission if a    plurality of HARQ processes are running simultaneously.

The invention has been described in detail with particular reference topreferred embodiments thereof and examples, but it will be understoodthat variations and modifications can be effected within the spirit andscope of the invention covered by the claims which may include thephrase “at least one of A, B and C” as an alternative expression thatmeans one or more of A, B and C may be used, contrary to the holding inSuperguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004).

1. A method for data transmission between a base station and a terminalin a communication system, comprising; transmitting data divided intotime segments from the base station to the terminal over a data channelshared by a plurality of terminals; and notifying the terminal from thebase station via one of at least two control channels, the base stationnotifying the terminal through control information comprising a seriesof pieces of control information, the control information also beingdivided into time segments, the base station notifying the terminal asto when data will be sent on the data channel to the terminal, themethod further comprising: monitoring the at least two control channelsat the terminal; receiving the control information at the terminal on afirst control channel of the at least two control channels in a firsttime segment; and generating an individual decision parameter for eachof the pieces of control information on the basis of the content of therespective piece of control information; wherein the control informationtransmitted over the first control channel has a first piece and asecond piece of control information, the first piece of controlinformation being transmitted two time segments before any datatransmission on the data channel, and the second piece of controlinformation being transmitted in at least one time segment subsequent tothe first time segment; a first individual decision parameter isgenerated for the first piece of control information and a secondindividual decision parameter is generated for the second piece ofcontrol information; if the first individual decision parameter isnegative, the data is not processed further and in the time segmentdirectly following the first time segment all control channels aremonitored; and if the first individual decision parameter is positiveand the second individual decision parameter is negative, the data isnot processed further and in a time segment directly following the timesegment of the second individual decision parameter, only the firstcontrol channel is monitored.
 2. The method according to claim 1 furthercomprising: defining which of the control channels should be monitoredin the time segment subsequent to the first time segment depending on anoverall decision parameter.
 3. The method in accordance with claim 2,wherein only the first control channel is monitored in the time segmentsubsequent to the first time segment if a positive overall decisionparameter is determined; and all control channels are monitored in thetime segment subsequent to the first time segment if a negative overalldecision parameter is determined.
 4. The method in accordance with claim2, wherein the subsequent time segment is the time segment directlyfollowing the first time segment.
 5. The method in accordance with claim2, wherein the data is transmitted over the data channel in packets. 6.The method in accordance with claim 5, wherein the first piece ofcontrol information identifies the terminal and the second piece ofcontrol information contains at least one of data channel configurationinformation, HARQ information, information about a packet size used fordata transmission, and information about modulation and coding schemesused to transmit the data.
 7. The method in accordance with claim 6,wherein if a positive overall decision parameter is determined, datatransmission via the data channel is delayed 2 time segments relative tothe time segment in which the control information began.
 8. The methodin accordance with claim 7, wherein, if a negative overall decisionparameter is determined, the data is not passed on to layers above thephysical layer of the OSI model.
 9. The method in accordance with claim1, wherein a positive overall decision parameter is generated if thecontrol information is classified as relating to the terminal and anegative overall decision parameter is generated if the controlinformation is classified as not relating to the terminal.
 10. Themethod in accordance with claim 1, wherein a positive individualdecision parameter is generated for the piece of control information ifthe piece of control information is classified as relating to theterminal and a negative individual decision parameter is generated forthe piece of control information, if the piece of control information isclassified as not relating to the terminal.
 11. The method in accordancewith claim 10, wherein the overall decision parameter is determined tobe positive if all individual decision parameters are positive.
 12. Themethod in accordance with claim 1, wherein the data is transmitted overthe data channel in packets.
 13. The method in accordance with claim 1,wherein the first piece of control information identifies the terminaland the second piece of control information contains at least one ofdata channel configuration information, HARQ information, informationabout a packet size used for data transmission, and information aboutmodulation and coding schemes used to transmit the data.
 14. The methodin accordance with claim 1, wherein if a positive overall decisionparameter is determined, data transmission via the data channel isdelayed in time relative to the time segment in which the controlinformation began.
 15. The method in accordance with claim 1, wherein ifa positive overall decision parameter is determined, data transmissionvia the data channel is delayed 2 time segments relative to the timesegment in which the control information began.
 16. The method inaccordance with claim 1, wherein, if a negative overall decisionparameter is determined, the data is not passed on to layers above thephysical layer of the OSI model.
 17. The method according to claim 1,further comprising: determining an overall decision parameter based onthe generated individual decision parameters; and selectively rejectingdata received on the data channel and the control information receivedon the first control channel depending on the overall decisionparameter.
 18. A terminal comprising: a receiver device to receive data;and a processor unit configured to execute a method for datatransmission between a base station and a terminal in a communicationsystem, the method comprising: transmitting data divided into timesegments from the base station to the terminal over a data channelshared by a plurality of terminals; and notifying the terminal from thebase station via one of at least two control channels, the base stationnotifying the terminal through control information comprising a seriesof pieces of control information, the control information also beingdivided into time segments, the base station notifying the terminal asto when the data will be sent on the data channel to the terminal, themethod further comprising: monitoring the at least two control channelsat the terminal; receiving the control information at the terminal on afirst control channel of the at least two control channels in a firsttime segment; and generating an individual decision parameter for eachof the pieces of control information on the basis of the content of therespective piece of control information, wherein the control informationtransmitted over the first control channel has a first piece and asecond piece of control information, the first piece of controlinformation being transmitted two time segments before any datatransmission on the data shared channel, and the second piece of controlinformation being transmitted in at least one time segment subsequent tothe first time segment; a first individual decision parameter isgenerated for the first piece of control information and a secondindividual decision parameter is generated for the second piece ofcontrol information; if the first individual decision parameter isnegative, the data is not processed further and in the time segmentdirectly following the first time segment all control channels aremonitored; and if the first individual decision parameter is positiveand the second individual decision parameter is negative, the data isnot processed further and in a time segment directly following the timesegment of the second individual decision parameter, only the firstcontrol channel is monitored.
 19. A cellular mobile radio communicationnetwork comprising: a base station; and a terminal for data transmissionwith the base station, the terminal comprising a receiver device toreceive data and a processor unit configured to execute a method fordata transmission between the base station and the terminal, the methodcomprising: transmitting data divided into time segments from the basestation to the terminal over a data channel shared by a plurality ofterminals; and notifying the terminal from the base station via one ofat least two control channels, the base station notifying the terminalthrough control information comprising a series of pieces of controlinformation, the control information also being divided into timesegments, the base station notifying the terminal as to when the datawill be sent on the data channel to the terminal, the method furthercomprising: monitoring the at least two control channels at theterminal; receiving the control information at the terminal on a firstcontrol channel of the at least two control channels in a first timesegment; and generating an individual decision parameter for each of thepieces of control information on the basis of the content of therespective piece of control information, wherein the control informationtransmitted over the first control channel has first and second piecesof control information, the first piece of control information beingtransmitted two time segments before any data transmission on the datachannel, and the second piece of control information being transmittedin at least one time segment subsequent to the first time segment; afirst individual decision parameter is generated for the first piece ofcontrol information and a second individual decision parameter isgenerated for the second piece of control information; if the firstindividual decision parameter is negative, the data is not processedfurther and in the time segment directly following the first timesegment all control channels are monitored; and if the first individualdecision parameter is positive and the second individual decisionparameter is negative, the data is not processed further and in a timesegment directly following the time segment of the second individualdecision parameter, only the first control channel is monitored.